text: Nuclear magnetic resonance decoupling (NMR decoupling for short) is a special method used in nuclear magnetic resonance (NMR) spectroscopy where a sample to be analyzed is irradiated at a certain frequency or frequency range to eliminate or partially the effect of coupling between certain nuclei.  NMR coupling refers to the effect of nuclei on each other in atoms within a couple of bonds distance of each other in molecules.  This effect causes NMR signals in a spectrum to be split into multiple peaks.  Decoupling fully or partially eliminates splitting of the signal between the nuclei irradiated and other nuclei such as the nuclei being analyzed in a certain spectrum.  NMR spectroscopy and sometimes decoupling can help determine structures of chemical compounds.